1. Field of the Invention
The present invention generally relates to a contact element retained in an electrical connector, and in particular to a contact element capable of effectively suppressing wicking of solder during a soldering process.
2. The Prior Art
Electrical connectors comprise contact elements made of conductive material retained in bores defined in an insulative housing for electrically engaging with pins of an electronic device inserted into the bores. Some electrical connectors, such as a mobile socket connector, comprise a movable cover and a fixed base. The contact elements are retained in bores defined in the base for being soldered to a circuit board. The cover defines holes corresponding to the bores of the base. An electronic device is positioned on the cover with pins thereof extending through the holes and partially into the bores whereby when the cover is moved with respect to the base, the pins are brought into engagement with the contact elements for establishing electrical engagement between the electronic device and the circuit board.
Each contact element of the connector comprises an anchoring section having barbs for fixing inside the corresponding bore and a loop section forming a resilient arm defining a narrow space. The loop section is connected to the anchoring section by means of a reduced connection section. A pin of the electronic device is initially received in the loop but does not make contact therewith. When the cover is moved, the pin is driven into the narrow space thereby securely engaging with the resilient arm.
One method of soldering the contact elements to the circuit board is to dip the circuit board into a molten solder bath or to dispose solder balls therebetween to be melted later. Molten solder flows into a gap formed between the contact elements and the circuit board and surrounds the contact elements thereby securing the contact elements to the circuit board after the solder is cured. During the soldering process, wicking of the molten solder from the anchoring section, through the neck section, to the loop section often occurs thereby adversely affecting electrical properties of the contact element.
Furthermore, the loop section which engages with the pin of the electronic device is often coated with a layer of gold for improving the conductivity thereof. Wicking of the gold layer to the anchoring section also commonly occurs. Although not affecting electrical properties of the contact element, such a method increases manufacturing costs since gold is a precious metal.
It is thus desirable to have a contact element capable of suppressing or eliminating the wicking problem.